This document relates to animal instrumentation.
Objective evaluation and diagnosis of animals is difficult for a variety of reasons. Most obviously, unlike humans, animals cannot easily communicate with a person who is evaluating, diagnosing, treating or training them. For example, a horse cannot communicate which limb or joint hurts or in what way it hurts or under what condition it hurts. Another difficulty, especially for large or fast animals such as horses, is that it is difficult to obtain objective and quantitative measurements of physical or physiological parameters on an animal, that are accurate, or reproducible, or reflect real-world conditions or are available in real-time. For example, it can be difficult and expensive to bring a horse into a facility with suitable measurement equipment to obtain accurate and reproducible measurements, and these do not represent real-world conditions and may not be available in real time. As a consequence, evaluation and diagnosis and treatment and conditioning are typically based on subjective and qualitative judgments of veterinarians, trainers or riders.
An important area of evaluation and diagnosis relates to lameness in horses. Competitive horses are valuable assets. Furthermore, they are physically fragile and are particularly susceptible to lameness. Experts estimate that at any one time at least 10% of all equine athletes are clearly lame or injured or out of condition in some way that prevents them attaining peak performance, and many more have subtle or chronic conditions that are difficult to detect or need monitoring.
Therefore, it is desirable to apply effective evaluation and diagnosis techniques to diagnose injury, to prevent injury, to enable the treatment of injury or to aid in recovery from injury in order to protect their value. In addition, it is desirable to improve the effectiveness of programs for training and conditioning. Once lameness is discovered, lengthy rehabilitation is often necessary. Significant effort and expense is expended on many competitive horses. Lameness temporarily or even permanently negates the benefit of such significant investment.
Detection and diagnosis of lameness in horses today is largely based on subjective and qualitative evaluation. Typical techniques involve observation to detect asymmetries in motion, gross evaluation of a stationary animal such as by palpitation of limbs, and use of anesthetic blocking of nerves to determine if lameness is alleviated, for example, by blocking pain from a particular joint. Note that in this last technique, although the horse may appear less lame, the underlying cause of lameness may in fact cause further damage to the horse during the evaluation.
Modern medical and veterinary techniques can involve some objective and quantitative monitoring of physical and physiological parameters. For example, monitoring of physiological parameters (for example, an EKG) during treadmill-based exercise is a well-established diagnostic technique for people. Treadmill-based techniques are also used for animals such as horses, with notably increased difficulty associated with the size of the animal and the limited means of communication with the animal. For example, a lengthy period of acclimatization and the use of tranquilizing drugs may be required.
In the veterinary domain, when objective measurements are sought, monitoring and diagnosis of accurate and reproducible physical and physiological parameters has generally included the use of treadmill-based techniques, video monitoring using optical markers to track limb position, or the use of force plates upon which a horse steps. These approaches do not necessarily reflect real-world conditions or support continuous monitoring.
Ambulatory monitoring has been attempted using a sensor for acceleration or recording heart rate and respiratory sounds for large animals, including horses. In general, these various objective measurements are either limited in the duration of the trial, or in the accuracy and reproducibility of the data, or performed for a limited set of parameters at a time, such as using a single two-axis accelerometer at 50 Hz for a few minutes, or a single sound sensor. In addition, they are typically very costly.
Other types of systems provide assistance for subjective evaluation, such as facilitating mark-up of video captured using commercially available consumer camcorders and using this assisted subjective data as the basis for analysis. These approaches have time resolution in the range of 50 Hz or 60 Hz (limited by the video frame rate) and a few centimeters in space (limited by video resolution), and generally lack of reproducibility because of the subjective assessment involved.